13231331221 has 2 divisors, whose sum is σ = 13231331222. Its totient is φ = 13231331220.

The previous prime is 13231331213. The next prime is 13231331261. The reversal of 13231331221 is 12213313231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6688786225 + 6542544996 = 81785^2 + 80886^2 .

It is a cyclic number.

It is not a de Polignac number, because 13231331221 - 2³ = 13231331213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13231331192 and 13231331201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13231331261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6615665610 + 6615665611.

It is an arithmetic number, because the mean of its divisors is an integer number (6615665611).

Almost surely, 2^13231331221 is an apocalyptic number.

It is an amenable number.

13231331221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13231331221 is an equidigital number, since it uses as much as digits as its factorization.

13231331221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 22.

Adding to 13231331221 its reverse (12213313231), we get a palindrome (25444644452).

The spelling of 13231331221 in words is "thirteen billion, two hundred thirty-one million, three hundred thirty-one thousand, two hundred twenty-one".